The present invention relates to a control system for a power drive for moving a movable closure, such as a sliding door along a fixed path between an open position and a closed position with respect to a portal defining a passage through a barrier, and more particularly to a control system for a sliding door system accommodating manual operation and powered operation of a sliding door of a vehicle in forward and rearward movement along a fixed path between an open position and a closed position with a striker latch mechanism, where a power striker moves the sliding door from a position adjacent the closed position to a fully closed and sealed position with respect to a frame defining the opening.
It is generally known to provide a sliding door for van-type vehicles, where the door is moved along a fixed path generally parallel to the side wall of the van for a major portion of its opening and closing movement. Typically, the sliding door of a van-type vehicle moves generally into the plane of the door opening during a portion of its respective final closing and initial opening movements, so as to be flush with the side wall when fully closed, and moves generally out of the plane of the door opening during its initial opening movement so as to be along side of, and parallel to, the side wall of the vehicle in a position generally to the rear of the door opening when fully opened.
In van-type vehicles having sliding door systems, typically upper and lower forward guide rails or tracks are attached to the top and bottom portions, respectively, of the portal defining an opening through the wall of the vehicle, and a rear guide rail is attached to the exterior of the side wall, at an elevation approximately midway between the elevation of the upper and lower forward guide rails. The respective forward end portions of the various guide rails are curved inwardly with respect to the vehicle body, and bracket and roller assemblies are fastened to the respective upper and lower forward ends of the sliding door, as well as to an intermediate position at the rear end of the sliding door. The bracket and roller assemblies are slidingly supported in the guide rails to guide the door through its opening and closing movements.
Movement of the sliding door through a major portion of the rearward track or guide rail extending generally parallel to the side wall of the vehicle requires high displacement with low force to achieve the transitional movement, since only frictional resistance and gravity resistances due to changes in grade must be overcome. The movement of the sliding door through a forward portion of the guide rail track, curved inboard with respect to the vehicle, requires a low displacement with high force. The forces associated with an elastomeric weather seal surrounding the door opening must be overcome and an unlatched striker or fork bolt on the door must be engaged by a corresponding fork bolt or striker at the rear portion of the van body door opening. During manual operation, sliding van doors are typically moved with great momentum through the entire closing movement in order to ensure full weather strip compression and latch operation at the end of such movement.
A typical standard automotive door latch assembly includes a striker, which can take the form of a pin or a U-shaped member, fixedly mounted in the door frame to project into the door opening and into the path of movement of a latch member mounted on the edge of the door, which includes the fork bolt therein. The latch member is typically movably mounted with respect to the door and arranged so that as the door approaches its closed position, the latch member will engage the striker and further closing movement of the door will move the latch member into safety latch position with respect to the pin, sometimes referred to as the secondary latch position, and further closing movement of the door will move the latch member into a primary latch position with respect to the pin, which positively retains the door against movement away from its closed position. It is generally known for at least part of the movement of the latch member into latched relationship with the striker to be resisted by a spring, and many users of sliding doors of this type habitually close the door with far greater force than necessary to overcome the spring bias. Greater force is generally required in the case of sliding doors, such as those employed in vans, where movement of the door through the final phase of movement to the fully closed position must compress a resilient door seal which extends around the entire periphery of the door opening.
Power striker devices have been proposed to overcome the high force requirements to move sliding doors into the fully closed position. Typically, the power striker devices are mounted on the door frame for powered movement between an outboard ready position with respect to the vehicle centerline where the latch is engaged with the striker and an inboard holding position where the striker holds the latch door in the fully closed position. It is still required in such systems to use high force or momentum in order to ensure that the latch engages the striker in the primary latch position prior to movement into the fully closed position. When the door is open, the striker is located in its outboard ready position. After closing translation of the door is complete, the latch on the door engages the striker and latches the door to the striker while the striker is still in the outboard position. The door may engage a limit switch on the door frame when in the outboard position to actuate a drive motor which, through appropriate mechanism, drives the striker to its inboard position, such that the latched engagement between the door and striker enables the pin to drive the door to the fully closed position. With this arrangement, a closing force sufficient to engage the latch to the primary latch position with respect to the striker needs to be applied. The powered movement of the striker provides the force necessary to compress the door seal. If the striker and latch do not reach the primary latch position with respect to one another, the powered movement of the striker from its outboard position to its inboard position would not be sufficient to bring the door to the fully closed position in sealed engagement with the frame around the periphery of the door opening. In such cases, the user may be required to reopen and close the door repeatedly until the latch and striker are disposed in the primary latch position with respect to each other when in the outboard position.
It is desirable in the present invention to provide a power drive system for moving a movable closure along a fixed path between an open position and a closed position with respect to a portal defining a passage through a barrier, such that latch bolt operation and weather strip compression can be accomplished at the end of such movement without requiring high momentum during the closing movement. It is also desirable in the present invention to provide a power drive for moving a closure with low momentum between its fully open position and fully closed position, such that the closure is moved into the primary latch position in a controlled manner without requiring additional mechanisms for engaging and moving the striker from the secondary latch position through the final portion of closing movement into the primary latch position. It is also desirable to provide a smaller power drive package for installation in a vehicle. Providing a power drive system that does not leave the drive member under load is desirable so that the drive member is not subjected to stretching forces over long periods of time and so that the need for slack take-up mechanisms is eliminated. It is further desirable to provide a power drive system with high closing force and low momentum to move the latch mechanism into the primary position with the power drive motor.
The present invention provides for automatically closing sliding doors such that the controller and motor drive translates the door along the entire fixed path during opening and closing movement to carry the fork bolt or striker on the door through the secondary latch position to the primary latch position to ensure full door security and sealing. The present invention physically pulls the door and connected striker or fork bolt into the corresponding fork bolt or striker connected to a frame defining the opening, through the secondary position and into the primary latch position, then initiates power striker motion to move the door into the weather strip seals surrounding the opening. The center rear hinge roller track is modified to accept a push/pull drive member and the translation means is coupled to the track for pushing and pulling the door open and closed. The advantage of the present invention is to pull the roller assembly and door fork bolt assembly into the power striker all the way to the primary latch position, passed the secondary position. Previously known power drive systems required high momentum to ensure proper closing of the sliding door assemblies for van-type vehicles. The power striker of the present invention then actuates a power striker to pull the door into the seals. If the translator motor has sufficient power, the latch mechanism could be fixed. The present invention provides mechanical advantage to pull the door into the primary latch position through the secondary latch position with a drive member, such as DYMETROL tape, and then uses a power striker to ensure sealing. The drive member pushes the door open during initial opening movement, which is an action that takes far less force than required to pull the door into the weather strip seals when the fork bolt and striker are in the primary latch position.
The power drive according to the present invention moves a movable closure along a fixed nonlinear path between an open position and a closed position with respect to a portal defining a passage through a barrier. Bracket means is operably connected to the movable closure. Guide means is connected to the barrier and operably engages the bracket means for guiding the bracket means along the fixed path between the open and closed positions of the movable closure. Elongated means is slidably disposed within the guide means and connected to the bracket means for driving the bracket means along the fixed path. Translator means operably engages with the elongated means for powering movement of the elongated means and the bracket means connected thereto with respect to the guide means along the fixed path.
A power striker apparatus according to the present invention includes an optionally controlled inertially activated impact cycle for engaging a striker, such as a pin or U-shaped member, with respect to a latch including a fork bolt movable from a secondary latch position to a primary latch position. The best door seals typically offer higher closing resistance, and require a large force or high momentum to close the doors. Often, a normal effort will only latch the striker in the secondary latch position, sometimes referred to as the safety latch position, even when the latching system is equipped with a power striker that allows striker engagement 12 mm to 25 mm away from the fully closed position where the door is in sealed engagement with the frame around the periphery of the door opening. The present invention provides means for snapping the spring loaded power striker into the door, when partially closed in the secondary latch position, causing the striker to move with respect to the fork bolt, such that the fork bolt moves into the primary latch position before the door can move outward from the inboard position. The power striker is then reactivated to pull the door into the fully closed inboard position in sealed engagement with the frame around the periphery of the door opening. The present invention eliminates the need for the operator to reopen and re-slam the door in order to bring the striker into the primary latch position with respect to the latch prior to operation of the power striker.
The power striker apparatus according to the present invention moves the engagement striker, such as a bolt pin or U-shaped bolt, outboard to ensure that the striker reaches the primary latch position with respect to the latch mechanism prior to the power striker being reactivated to draw the door into the fully closed and sealed position. If the striker and latch mechanism are only engaged in the secondary latch position, or safety position, normally the door must be reopened and a second attempt at closing the door must be attempted by the operator. The present invention provides means for snapping or restriking the striker member outward to quickly drive the striker into the primary latch position with respect to the door latch mechanism before the door has a chance to move outward. This method of operation could produce audible sounds, and therefore, would be activated only if the striker and latch mechanism did not achieve the primary latch position, or if the required door velocity to latch the striker into the primary latch position with respect to the latch mechanism is not normally achievable. The present invention may include a method of determining whether primary or secondary latch positions have been achieved, by monitoring the minimum amount of time required to achieve the desired position. A longer time period would be associated with reaching a primary latch position, since the force to close is higher and higher torque is required of the motor and associated gear box, slowing the motor and associated gear box, thereby requiring more time to close when in the primary latch position. In the alternative, the door ajar switch can be used as an input signal to the controller logic to determine if the door is successfully closed.
The present invention can include biasing means for preloading a striker arm clockwise towards a stop, where the striker pin will be in a first position. The biasing means, such as a spring, is reacted against a spring pin and is centered on a pivot member. Motor means is also provided for driving a worm and gear assembly which in turn drives a second worm and gear assembly. The gear portion of the second worm and gear assembly is pinned to a drive arm which carries a roller fastened thereto. When the drive arm is driven clockwise, the roller is caused to engage the roller cam, the striker arm is caused to rotate counterclockwise from the first position to a second position, where a switch means is provided for signaling a controller means for stopping the motor with the roller in a second position and the striker pin in a second position. At this point, the door system logic controller means is provided for determining if the door is closed, and if the door latch fork bolt is in the primary position. If the door latch fork bolt or striker is in the primary position, the controller means will reset and be prepared to operate the striker clockwise from the second position to the first position by rotating the drive arm counterclockwise from the second position to the first position when it is desired to open the door. This typically would be a quiet operation. If the fork bolt is determined to be in the partially latched secondary position, sometimes referred to as the safety latch position, through a separate motor, actuator, controller logic, then the drive arm is rotated clockwise beyond the second position, such that the roller rotates past the end of the cam surface and the striker arm is spring propelled to inertially snap back to the first position against the stop. The spring load and striker arm inertia must be sufficient to carry the fork bolt or striker into the primary position. The drive arm then continues clockwise until it engages the roller cam at the first position, where it is ready for another cycle to move the door into the fully closed position with the latch and pin in the primary latch position.